S
M
T
W
T
F
S
26
86°
53°
27
84°
55°
28
85°
58°
29
89°
57°
30
90°
56°
31
86°
55°
1
86°
55°
2
85°
54°
3
81°
55°
4
88°
55°
5
84°
56°
6
86°
53°
7
80°
53°
8
84°
54°
9
84°
57°
10
88°
56°
11
88°
57°
12
89°
56°
13
90°
57°
14
89°
55°
15
85°
53°
16
83°
52°
17
82°
54°
18
86°
58°
19
86°
55°
20
85°
53°
21
80°
55°
22
84°
54°
23
86°
56°
24
86°
53°
25
81°
54°
26
85°
56°
27
81°
51°
28
81°
52°
29
83°
55°
30
85°
51°
31
82°
49°
1
79°
50°
2
80°
51°
3
83°
56°
4
84°
52°
5
85°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Boulder
Boulder's August 2026 forecast shows daily high temperatures ranging from 79° to 90°, with overnight lows between 49° and 58°. The average high for August is 85° with an average low of 54°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Boulder. See also: September | October | November.
